1. Field of the Invention
The present invention relates to a navigation system installed in a vehicle such as a car, and more particularly to a navigation system that has a function of printing travel records.
2. Description of the Related Art
FIG. 6 shows a block diagram of a prior car navigation system. In FIG. 6, the car navigation system comprises a central processing unit 11, abbreviated to CPU hereafter, that processes data, memory 12 that stores processing programs, data, and the like, an input device 13 that takes data from the user, a position measuring unit 14 that measures the current position, a display unit 15 that displays maps, travel records, and the like, a display controller 16 that controls display unit 15, a CD-ROM player 17 that drives a CD-ROM (compact disk ROM) that is a storage medium for map information and the like, a CD-ROM controller 18 that controls CD-ROM player 17, and a memory card controller 20 that has an interface function for connecting a memory card 19 that stores travel-record data and the like. Memory 12 is composed of ROM and RAM and stores processing programs, travel-record data, map screen information, and the like. CPU 11 performs processing for screen control, position calculation, route calculation, route guiding, and the like. Position measuring unit 14 is composed of a GPS (global positioning system) and others and measures the longitude and latitude information about the current position to send it to CPU 11. Memory card 19 is a detachable storage medium and records and preserves travel routes, travel tracks, and the like. The information about the recorded data is retrieved by the user's input through input device 13 and displayed on display unit 15.
In the prior car navigation system, position measuring unit 14 measures the current position, and CPU 11 accesses CD-ROM player 17 based on the position information to display map screen information including the current position on display unit 15. Further, CPU 11 executes the procedures of the programs stored in memory 12 following the input through input device 13 to perform route searching, route guiding including aural guiding, displaying of a route chart, and the like. CPU 11 also preserves travel track records in the connected memory card 19, and can read out a past travel record therefrom to display on display unit 15 for confirmation.
The prior car navigation system can display on the screen of display unit 15 the current route and past travel records recorded on memory card 19, and also can make a copy for each screen. However, it does not have a function of printing past travel records recorded on the memory card. Therefore, it cannot print out travel records that are necessary for operating control of vehicles for business use, such as travel positions, travel distance, travel time, and the like.